Second-phase nucleation on an edge dislocation

TL;DR

This paper develops a Ginzburg-Landau based model to analyze second-phase nucleation around dislocations in crystals, providing insights into phase behavior and critical energies, with applications to zirconium alloys.

Contribution

It introduces a Ginzburg-Landau model with sextic terms for second-phase nucleation near dislocations, linking classical and phase-field theories.

Findings

Derived ground state solutions for the order parameter.

Presented a phase diagram showing tricritical behavior.

Applied the model to hydride nucleation in zirconium alloys.

Abstract

A model for nucleation of second phase at or around dislocation in a crystalline solid is considered. The model employs the Ginzburg-Landau theory of phase transition comprising the sextic term in order parameter in the Landau free energy. The ground state solution of the linearized time-independent Ginzburg-Landau equation has been derived, through which the spatial variation of the order parameter has been delineated. Moreover, a generic phase diagram indicating a tricritical behavior near and away from the dislocation is depicted. The relation between the classical nucleation theory and the Ginzburg-Landau approach has been discussed, for which the critical formation energy of nucleus is related to the maximal of the Landau potential energy. A numerical example illustrating the application of the model to the case of nucleation of hydrides in zirconium alloys is provided.